Chinook RV

Palolojack-nice work on the new trans cooler...pics were helpful.
I just got back from a week of traveling in the Northeast Kingdom of Vermont, with Rig fully loaded (covered bikes up front and pack rafts, and solar panels on rear with full water and propane). It was hot all week (around 85 during the days). I had competed the radiator flush, and confirmed with my mechanic that fan and all cooling were in spec. So, here are the temp readings I experienced:
Cruising at 72-75 on the interstate with AC: water pretty steady at 207 with occasional spikes no higher than 215 before coming back down, and trans fluid temp steady at 195-197
Cruising at 65 on the interstate with AC: water temp steady at around 198-202 with some blips to 207 before coming back down, and trans fluid temp steady at 185-190
Driving 2-lane hilly roads at 50 or so with AC: water temp varied more (as one would expect) between 192-202, and trans temps 180-190.
Climbing steeper grade at sped (60 maybe?) with AC: water temp 207-215 with blip to 217 before coming back down, and trans fluid temp getting up to 200 with blip to 202.
Based on all the good discussion on this forum, other reading, and conversations with my mechanic, I am feeling OK with all of those numbers. Sure, would arguably be better for me to back off a bit on the interstate, and not push so much on the hills...but so would eating more veggies. OK...so maybe I will throttle back a bit on the hills, but I just can't seem to bring myself to cruise at less than 70 for very long. Oh well.
David

Scott-
From a results standpoint, I've only done about 15-20 minute drives post install so not much data. With a heavy foot and some hills I struggled to get the trans temp above 150, so it will be interesting to see it in action on a triple digit day climbing grades. I live on the coast so I don't see much over 80 degrees around town. The K&N CAI was a nice upgrade, but pricey for the return on investment. Nice sound, and not overwhelmingly loud as a negative I've experienced in other vehicles. It has a noticeable punch at the top end, and certainly no loss at the bottom where the V10 typically shines. I'll update when I get on my next long trip with some heat to it.

deppstein-
I was contemplating the engine heat you're experiencing, and I had a thought about something I ran into while installing a front hitch on mine. It might be different on various years, but my front hitch installation required removing a lower shroud that directed air to the radiator through the bottom of the bumper. It didn't concern me at the time as etrailer.com's video shows this as a normal step, but now I feel like it could allow air to flow through the path of least resistance and blow right past the lower section of the radiator. This would only effect moderate to highway speeds where your fan isn't doing much, which sounds like your experience. It could be in my head, but I feel like mine is slightly hotter now post front hitch install. Maybe the combo of the missing shroud plus the bike covers are causing the warmer temps you're seeing. Just a thought I had while reading the thread.
Anyways, here are some more pics of the cold air intake and my Chinook exterior for rig reference.

Palolojack--I just got done watching the e-trailer front hitch install video and definitely think you are on to something...I had my hitch installed, so was not aware of the process of removing the plastic shroud. Seems that without it in place, air coming in through the front openings below the bumper would indeed just blow right under the radiator instead of being directed upward. I'll have to go out and crawl around under there to see if there is any simple way to rig something up after the fact. Has anyone else played around with this...any and all suggestions welcome.
David

If youre running a 195 degree thermostat youre never going to get the engine or transmission temps below where your currently at. I dont see anything abnormal here considering you said you were driving in 101 degree temps with the front grill blocked off with bicycles.

If you have a 195 degree thermostat your engine temperature is never going to go below that 195 degrees, anything attached to that engine is going to reflect that same temperature within a few degrees due simply to heat convection. That said, if your thermostat is 195 degrees that means it doesnt open until the engine and coolant is at a minimum of a 195 degrees. That means the coolant is "ALWAYS" going to be a minimum of 195 degrees before coolant is allowed to flow threw the radiator. That also means the transmission is also going to run at nothing less than 195 dgrees. Add some bicycles up front, crank the suns heat up to 101 degrees and things are just going to run hotter. Attach a secondary tranny cooler to a radiator thats trying to cool 195 degree coolant and its going to run at a minimum of 195 degrees. Dont believe me, try putting your hand on the radiator after the engine has been running a couple of hours. The feed side of the radiator is going to be the same temp as the engine. The coolant only remains in the radiator for a limited moment of time. That means it has a short period of time to disipate heat from the coolant before it is returned to the engine to absorb more heat.

If you arent going to address determining what thermostat you have in the engine, then youre just wasting time and money because your never going to get the temperature below what the thermostat is rated for. You can throw a million fans on it and that thermostat is still not going to open until that engine is running at a minimum of 195 degrees.

Find out which thermostat you have (i can guaruntee that you have a 195 degree) install a 185 degree unit or lower if you can locate one. I think i actually have a 165 degree thermostat stashed someplace that i bought from a ford dealer when i was in New Mexico, i never installed it i just bought it as insurance because it was so dam hot when i was down there.

If your engine and tranny are running 10 degrees hotter than the thermostat is rated with an outside temp of 101 degrees, installing a 185 should theoretically drop your temps down to 195 providing everything else is functioning properly. Your temps are not out of line for the conditions youre subjecting the vehicle to IMO. Thast not to say they arent high, thats saying they arent a surprise. The obvious best solution would be to locate a better radiator, tranny cooler, and thermostat.

Oh, the other issue is that you dont want to go so low with the thermostat rating that the ECU thinks the engine hasnt reached full operating temperature. Which is going to require more than a 10 or 15 degree temp drop in your case. Also in regards to the secondary tranny coolers, you should have one line going in the lower portion of your radiator, one line coming out of the radiator to your secondary cooler, and then a line returning the fluid to your tranny. More than once i saw guys disconnect both lines from the radiator and connect them directly to the secondary tranny cooler thinking it was somehow a complete replacement.

BluGo is better at explaining stuff more decisively than i can, i just tend to confuse people and or get them upset.

Dougm--Good Post! Makes sense.
Just to clarify, the outside temps in VT on this trip were in the mid-80's...but I think everything you are saying still makes sense. I did crawl around underneath the engine to see if there was any easy way to increase air flow from below--not really without a whole lot of fussing and loss of ground clearance. So I'm gong to talk to my mechanic about installing a 185 degree thermostat. I'll report out what he has to say. Thanks again to all contributors to this thread...I continue to marvel at the wealth of knowledge and information that continues to come my way.
David

Right, it could be 80 degrees outside with 85 percent humidity. That engine is still going to run at whatever temperature its thermostat is rated at, its never going to get below that 195 degrees, if it does anything its going to climb higher. im not trying to imply that a thermostat is a cure for a plugged radiator or a failing water pump. Im going on the assumption that you have eliminated the other obvious causes. I understand your concern is the tranny temp, however the engines ability to remain cool will directly affect your transmission temperature. Thats my opinion, take it for what its worth, probably about 2 cents in todays market. You have to have a starting point in troubleshooting, you cant just start throwing money and bandaids at a problem. Start with the obvious and follow an orderly process of elimination if the problem isnt blatantly obvious. The engine has an entire radiator dedicated to keeping it cool, your tranny only has a small tube in the bottom of that huge radiator to help keep it cool, plus whatever secondary unit you have. If the radiator is starting to get plugged up not only is the cooling system going to struggle to keep the engine cool, its also going to raise the transmission temperature due to its inability to disipate heat fast enough to keep up with rising temperatures.

Check this out, its an all aluminum radiator for the E-series versus our cheap plastic ones and it has a lifetime warranty, whatever lifetime references
Someone had a plastic radiator sprout a leak and they ran across this one on another forum.
https://shop.performanceradiator.com/in ... ct_id=5235

I just completed a full check and flush of the cooling system, so feeling OK on that front...for now (I'll keep the all Aluminum option in mind though). I also checked hose connections from the trans cooler after reading your post...and happy to report that all-good on that score as well. The mechanics that put in my Jasper transmission in NM did a good job. Thanks again for keeping me headed in the right direction.
David